Amsahr Replacement Battery for Dell 3721, Inspiron: 14(3421), 14R(5421), 14R(5437), 15(3521), 15R(5521), 15R(5537) 18 Months Manufacturer Warranty, 100% Satisfaction Guaranteed. 100% Compatible Non-OEM : Lithium Ion (Li- ion) Long Life Battery: Rechargeable with No Memory Effect and Power Surge Protection. 40 Wh, 14.8 Volts & 4 Cell Protective Retail Packaging, Each Product is Sealed with Anti-Static Shield Sleeve. Exclusive Offering of High Performance, Long Lasting, and Durable Grade A Cell Battery 18 Months Manufacturer Warranty, 100% Satisfaction Guaranteed. 100% Compatible Non-OEM : Lithium Ion (Li- ion) Long Life Battery: Rechargeable with No Memory Effect and Power Surge Protection. 36WH, 14.8 Volts & 4 Cell Protective Retail Packaging, Each Product is Sealed with Anti-Static Shield Sleeve. Replacement Laptop Battery for Dell 3721 Compatible Non-OEM Long Life, Li-ion Battery Rechargeable with No Memory Effect and Power Surge Protection. Exclusive Offering of High Performance, Long Lasting. Durable Grade A Cell Battery.